The Tide & Palm guide
What are polarised sunglasses?
If you've ever squinted across the sea on a bright day, you've met glare. Polarised lenses are built to remove it — here's what that actually means, in plain English.
The short answer
Ordinary sunglasses darken everything you look at. Polarised sunglasses do that too — but they also contain a special filter that blocks the harsh, horizontal light that bounces off flat surfaces like water, wet roads, car bonnets and sand. That bounced light is glare, and it's what makes your eyes tired and forces you to squint even behind dark lenses.
What does "polarised" actually do?
Light normally scatters in every direction. When it hits a flat surface it flattens out and travels horizontally — which is why glare off the sea feels so much sharper than ordinary daylight. A polarised lens has a vertical filter laminated into it. Vertical light passes through; horizontal glare doesn't. The result is a picture that's noticeably clearer and more comfortable, with truer colour.
The difference is most dramatic around water. With polarised lenses you can often see into the water rather than just the sheet of reflected sky on top of it — which is why sailors, anglers and lifeguards have worn them for decades.
Who are they for?
- Anyone who spends time near the sea, rivers or lakes
- Drivers — they cut glare from wet roads and other cars' windscreens
- Walkers, runners and cyclists on bright days
- Anyone whose eyes feel tired or headachy after a day outside
A quick at-home test
Hold your sunglasses up to a phone or laptop screen and slowly rotate them 90 degrees. If the screen appears to darken or go almost black through the lens at one angle, the lenses are genuinely polarised — the lens filter and the screen's own polarising layer are crossing over. It's a ten-second check that any pair claiming to be polarised should pass.
Polarised and UV protection are different things
One common mix-up: polarisation and UV protection are separate features. Polarisation is about comfort and clarity; UV protection is about safety. A dark lens without proper UV filtering is actually worse than no sunglasses at all, because your pupils open wider behind the tint and let more harmful light in. Look for UV400 — it blocks 99–100% of UVA and UVB rays. Every Tide & Palm frame pairs polarised lenses with full UV400 protection, so you never have to choose between the two.
Are there any downsides?
A couple of small ones. Polarised lenses can make some LCD screens (older car dashboards, some phones) look patchy at certain angles, and they can hide the icy patches skiers sometimes rely on spotting by glare. For everyday wear, driving, the beach and the water, they're a clear upgrade.
Choosing a pair
Once you've decided on polarised, the rest is about fit and style: a frame that sits comfortably on your nose and ears, lenses large enough to cover your field of vision, and a shape you actually enjoy wearing. Spring hinges and a lightweight frame make a real difference over a long day. All of our frames are hand-checked, polarised and UV400 — so it's purely a question of which one suits you.
